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    <title>Document</title>
    <style>
        .active{
            background: blue;
        }
    </style>
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<body>
      <script>
          var body=document.querySelector('body');
          var ul=document.createElement('ul');
    
          ul.className='list';

          body.appendChild(ul)

          for(var i=0;i<5;i++){
              var li=document.createElement('li')
              li.className='active'
              li.style.fontSize='40px'
              li.innerHTML='item'+i
              ul.appendChild(li)
          }

      </script>
</body>
</html>